Mobile devices are required to perform more and more functions. As a result, the mobile devices have higher capacity batteries in order to have reasonable operating time. In order to charge the higher capacity batteries, larger charging currents are needed to keep the charging time reasonable. The popular charging interface for charging mobile devices is the Universal Serial Bus (USB) interface. More specifically, a micro USB interface in the mobile device. However, higher charging currents through a micro USB interface can have power dissipation problems due to the smaller interface and wear of cables and connectors.